[dpdk-dev] [PATCH v4 08/14] virtio: pci: extend virtio pci rw api for vfio interface

[Santosh Shukla]

On Fri, Jan 15, 2016 at 11:57 AM, Yuanhan Liu
<yuanhan.liu at linux.intel.com> wrote:
> On Thu, Jan 14, 2016 at 06:58:31PM +0530, Santosh Shukla wrote:
>> So far virtio handle rw access for uio / ioport interface, This patch to extend
>> the support for vfio interface. For that introducing private struct
>> virtio_vfio_dev{
>>       - is_vfio
>>       - pci_dev
>>       };
>> Signed-off-by: Santosh Shukla <sshukla at mvista.com>
> ...
>> +/* For vfio only */
>> +struct virtio_vfio_dev {
>> +     bool            is_vfio;        /* True: vfio i/f,
>> +                                      * False: not a vfio i/f
>
> Well, this is weird; you are adding a flag to tell whether it's a
> vfio device __inside__ a vfio struct.
>
> Back to the topic, this flag is not necessary to me: you can
> check the pci_dev->kdrv flag.
>

yes, I'll replace is_vfio with pci_dev->kdrv.

>> +                                      */
>> +     struct rte_pci_device *pci_dev; /* vfio dev */
>
> Note that I have already added this field into virtio_hw struct
> at my latest virtio 1.0 pmd patchset.
>
> While I told you before that you should not develop patches based
> on my patcheset, I guess you can do that now. Since it should be
> in good shape and close to be merged.

Okay, Before rebasing my v5 patch on your 1.0 virtio patch, I like to
understand which qemu version support virtio 1.0 spec?
>
>> +};
>> +
>>  struct virtio_hw {
>>       struct virtqueue *cvq;
>>       uint32_t    io_base;
>> @@ -176,6 +186,7 @@ struct virtio_hw {
>>       uint8_t     use_msix;
>>       uint8_t     started;
>>       uint8_t     mac_addr[ETHER_ADDR_LEN];
>> +     struct virtio_vfio_dev dev;
>>  };
>>
>>  /*
>> @@ -231,20 +242,65 @@ outl_p(unsigned int data, unsigned int port)
>>  #define VIRTIO_PCI_REG_ADDR(hw, reg) \
>>       (unsigned short)((hw)->io_base + (reg))
>>
>> -#define VIRTIO_READ_REG_1(hw, reg) \
>> -     inb((VIRTIO_PCI_REG_ADDR((hw), (reg))))
>> -#define VIRTIO_WRITE_REG_1(hw, reg, value) \
>> -     outb_p((unsigned char)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg))))
>> -
>> -#define VIRTIO_READ_REG_2(hw, reg) \
>> -     inw((VIRTIO_PCI_REG_ADDR((hw), (reg))))
>> -#define VIRTIO_WRITE_REG_2(hw, reg, value) \
>> -     outw_p((unsigned short)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg))))
>> -
>> -#define VIRTIO_READ_REG_4(hw, reg) \
>> -     inl((VIRTIO_PCI_REG_ADDR((hw), (reg))))
>> -#define VIRTIO_WRITE_REG_4(hw, reg, value) \
>> -     outl_p((unsigned int)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg))))
>> +#define VIRTIO_READ_REG_1(hw, reg)                                   \
>> +({                                                                   \
>> +     uint8_t ret;                                                    \
>> +     struct virtio_vfio_dev *vdev;                                   \
>> +     (vdev) = (&(hw)->dev);                                          \
>> +     (((vdev)->is_vfio) ?                                            \
>> +     (ioport_inb(((vdev)->pci_dev), reg, &ret)) :                    \
>> +     ((ret) = (inb((VIRTIO_PCI_REG_ADDR((hw), (reg)))))));           \
>> +     ret;                                                            \
>> +})
>
> It becomes unreadable. I'd suggest to define them as iniline
> functions, and use "if .. else .." instead of "?:".
>
>         --yliu